Shaping the photoluminescence spectrum of ZrO2:Eu3+ phosphor in dependence on the Eu concentration

A series of Eu doped ZrO2 micropowders with different concentration of Eu (0.04-6.85 wt%) was obtained by incipient wetness impregnation followed by annealing at 1200 degrees C. X-ray diffraction analysis revealed that the phase composition of samples with the minimum Eu concentrations in the series is represented predominantly by the monoclinic phase. An increase in the Eu content leads to proportional stabilization of the tetragonal phase, and at concentrations above 2.00 wt% the cubic ZrO2 phase is also stabilized. It was shown that red luminescence of the samples is responsible for the radiation transitions D-5(0) -> F-7(J) (J = 0-4) in Eu3+ ions. It was shown that shaping the photoluminescence spectrum of monoclinic ZrO2:Eu3+ phosphor depending on Eu concentration is related to the stabilization of ZrO2 tetragonal and cubic structure by Eu3+. The local symmetry of Eu3+ in each of the detected phases was identified. The lifetime of Eu3+ in the monoclinic phase of ZrO2 does not depend on the dopant concentration and is in the range of 0.73-0.81 ms, whereas in the tetragonal phase it first increases from 1.7 to 1.85 ms and then reaches a maximum at a concentration of 2.00 wt%. The absolute quantum yield increases from 1.6 to 4.8% over the entire range of Eu concentration.